The "COVID-19 infection self-test and alert system" (hereinafter referred to as "COVID-19 self-test applet") jointly developed by Beijing Tsinghua Changgung Hospital, Institute for precision medicine, artificial intelligence of Tsinghua University was launched on February 1，2020. This survey was also advocated by Chinese Medical Doctor Association. Residents , or even oversea Chinese people，according to their actual healthy situation, after answering questions online, the system will conduct intelligent analysis, make disease risk assessment and give healthcare and medical guidance. Based on the Internet population survey, and referring to the diagnosis and screening standards of the National Health Commission of the People's Republic of China, investigators carried out the mobile applet of Internet survey and registry study for the Internet accessible identifiable population, so as to screen the suspected population and guide the medical treatment.
